CROSS AXIS TORQUE LIMITER FOR HELICOPTER AUTOPILOT

A helicopter flight control system employs coupled torque limiters in the rotor cyclic pitch axis and collective pitch axis for airspeed and vertical path control, respectively. When the collective torque limit is reached, the cyclic pitch axis is automatically transferred to favor vertical path control. A synchronizer circuit is provided for assuring smooth acceleration transition to reduce accrued airspeed errors when the engine torque limit is no longer commanded.